The trend of emphasizing attractiveness of the outer design as well as easy operability of the current communication electronic devices is only growing. As such, the diversification of an input unit represented by a keyboard or a keypad became an important feature. Through these input units usually found in various kinds of display systems such as portable terminals, mobile phones, tablet computers, laptop computers, and even smart TVs (often referred to as connected TV), and the like, information is provided to a user. Recently, with the development of electronic devices, a method of inputting command signals using touch operations is widely used rather than using operation keys, dials, and the like.
A touch input device, constitutes an interface between a user and a communication device using various kinds of displays, enables the user to transfer information to the communication device as the user simply contacts or approaches close to a touch pad or a touch screen using input means such as his/her finger or a touch pen. Because of its easy operability, the touch input device can be widely used by men and women of all ages. Accordingly, the touch input device is applied to various display devices including an Automated Teller Machine (ATM), a Personal Digital Assistant (PDA), a mobile phone, and etc., which also can be applied to various locations and fields, for example, banks, public offices, sightseeing, traffic guidance, and etc.
Recently, efforts have been made to apply touch input devices to health- or medical-related equipment and vehicles. Particularly, the use of a touch panel is increasing because it can be either integrated in a touch screen or separated from the display system. More functions of inputting gestures or moving a point using touch operation has been developed. Studies on improving a recognition rate of gestures input by touch input devices are conducted.
Exemplary methods of implementing a touch input device in such applications include a resistive method, a capacitive method, a Surface Acoustic Wave (SAW) method, and a transmitter method. When an input means such as a finger contacts any one(s) of touch input devices to detect a position at which an input occurred, the touch input device using the capacitive method generates electrode patterns intersecting each other, and detects a change in capacitance therebetween. There is also a type of applying the same in-phase potential to both ends of a transmissive conductive film, and detecting weak current flowing when capacitance is formed by input means such as a finger contacts or approaches close to the transmissive conductive film to thus detect a position at which an input occurred.
Generally, the touch input device has a 2-panel laminate structure in which a first panel including a plurality of first sensing patterns arranged in the first direction (for example, an x-axis direction) on a first substrate. A plurality of first metal patterns to electrically connect the first sensing patterns to a sensor circuit for calculating the positions of the first sensing patterns is disposed on a second panel including a plurality of second sensing patterns arranged in the second direction (for example, an y-axis direction) on a second substrate. A plurality of second metal patterns electrically connect the second sensing patterns to the sensor circuit for calculating the positions of the second sensing patterns, using an adhesive.
Korean Laid-open Patent Application No. 10-2008-0110477 discloses a capacitive type touch panel of a two-layered structure of one sheet type.
Typical methods of manufacturing a touch input device include a method of using Indium Thin Oxide (ITO) that is a transparent electrode to be applied to a touch panel; a method of using a metal mesh; and a method of using a Flexible Printed Circuit Board (FPCB).
These methods require many processing stages, complicated processing, and high manufacturing costs. Particularly, the method of using ITO causes a problem of a rise in product price due to the use of a rare material whose price is usually high.
Furthermore, these methods are vulnerable to external vibrations, impacts or high temperature since they use an adhesion method, and hence the product durability deteriorates rapidly.